A large scale service provider network, e.g., a Next Generation Network (NGN), may comprise multiple regional access offices connected to a backbone network, e.g., an Internet Protocol (IP) backbone network. The service provider may enable an access office to serve as a protection site for another access office. For example, if a network failure affects the ability to reach a first access office, the service provider may enable a second access office to serve as a protection site such that customers who typically register at the first access office may utilize the second access office in the event of a failure. However, the majority of calls (outbound and inbound) for the customers who re-register at a protection site are for a customer phone number served by the first access office. For example, the majority of calls between re-registered (re-homed) customers and Public Switched Telephone Network (PSTN) phone numbers are served by media gateways in the first access office. Hence, the majority of voice media packets for calls for the re-homed customers associated with PSTN phone numbers will traverse links between one or more access offices and the backbone network multiple times. In other words, the re-homed customers will use the second access office to reach the first access office. This increase in traversals due to the re-homing of a portion of the customers for the service provider consumes a significant capacity of the network.
In some failure scenarios, e.g., failure of all public connections to a first access office, a large number of customers may be affected. If a large number of customers re-register at one or more session border controllers located at the protection site for the access office, the majority of calls for the re-homed customers for PSTN phone numbers may still need to use media gateways in the first access office. Thus, a massive number of customers re-registering at the protection site may result in the network being overloaded and performance being degraded for all calls.